Apparatus and methods for true power detection

ABSTRACT

Apparatus and methods for true power detection are provided herein. In certain embodiments, a power amplifier system includes an antenna, a directional coupler, and a power amplifier electrically connected to the antenna by way of a through line of the directional coupler. The power amplifier system further includes a first switch, a second switch, and a combiner that combines a first coupled signal received from a first end of the directional coupler&#39;s coupled line through the first switch and a second coupled signal received from a second end of the directional coupler&#39;s coupled line through the second switch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/749,758, filed Jan. 22, 2020 and titled “APPARATUS AND METHODS FORTRUE POWER DETECTION,” which claims the benefit of priority under 35U.S.C. § 119 of U.S. Provisional Patent Application No. 62/798,779,filed Jan. 30, 2019 and titled “APPARATUS AND METHODS FOR TRUE POWERDETECTION,” each of which is herein incorporated by reference in itsentirety.

BACKGROUND Technical Field

Embodiments of the invention relate to electronic systems, and inparticular, to radio frequency (RF) electronics.

Description of Related Technology

A communication system can include a transceiver, a front end, and oneor more antennas for wirelessly transmitting and/or receiving signals.The front end can include low noise amplifier(s) for amplifyingrelatively weak signals received via the antenna(s), and poweramplifier(s) for boosting signals for transmission via the antenna(s).

Examples of communication systems include, but are not limited to,mobile phones, tablets, base stations, network access points,customer-premises equipment (CPE), laptops, and wearable electronics.

SUMMARY

In certain embodiments, the present disclosure relates to a poweramplifier system. The power amplifier system includes a power amplifierconfigured to receive a radio frequency signal at an input and to outputan amplified radio frequency signal at an output, an antenna configuredto transmit the amplified radio frequency signal, a directional couplerhaving a through line and a coupled line, the through line electricallyconnected between the output of the power amplifier and the antenna, anda combiner configured to generated a combined signal based on combininga first coupled signal from a first end of the coupled line and a secondcoupled signal from a second end of the coupled line.

In some embodiments, the power amplifier system further includes a powerdetector configured to generate a power detection signal based ondetecting a power of the combined signal. According to a number ofembodiments, the power amplifier system further includes ananalog-to-digital converter configured to digitize the power detectionsignal. In accordance with several embodiments, the power detector is aroot mean square power detector.

In various embodiments, the combiner is a quadrature hybrid. Accordingto some embodiments, the power amplifier system further includes atermination impedance, and the quadrature hybrid includes a firstterminal electrically connected to the first end of the coupled line, asecond terminal electrically connected to the second end of the coupledline, a third terminal configured to output the combined signal, and afourth terminal electrically connected to the termination impedance.

In several embodiments, the directional coupler has a coupling factor ofat least 16 dB.

In some embodiments, the directional coupler has a directivity of atleast 10 dB.

In various embodiments, the directional coupler is implemented as a slowwave coupler.

In a number of embodiments, the through line is substantially U-shapedand the coupled line is substantially U-shaped. According to someembodiments, the directional coupler further includes a plurality ofcoupling conductors extending beneath the through line and the coupledline.

In several embodiments, the power amplifier system further includes aswitch including an input electrically connected to the first end of thecoupled line, a first output configured to provide the first coupledsignal to the combiner in a first state of the switch, and a secondoutput configured to output a forward power signal in a second state ofthe switch.

In some embodiments, the amplified radio frequency signal is amillimeter wave signal.

In certain embodiments, the present disclosure relates to a method ofpower detection in a radio frequency communication system. The methodincludes amplifying a radio frequency signal to generate an amplifiedradio frequency signal using a power amplifier, providing the amplifiedradio frequency signal from an output of the power amplifier to anantenna by way of a through line of a directional coupler, andgenerating a combined signal based on combining a first coupled signalfrom a first end of a coupled line of the directional coupler and asecond coupled signal from a second end of the coupled line of thedirectional coupler.

In a number of embodiments, the method further includes generating apower detection signal based on detecting a power of the combinedsignal. According to several embodiments, the method further includesdigitizing the power detection signal using an analog-to-digitalconverter. In accordance with various embodiments, the method furtherincludes controlling a transmit power of the radio frequencycommunication system based on the digitized power detection signal.According to some embodiments, controlling the transmit power includestuning an output matching network of the power amplifier based on thedigitized power detection signal. In accordance with severalembodiments, controlling the transmit power includes adjusting a bias ofthe power amplifier based on the digitized power detection signal.According to various embodiments, controlling the transmit powerincludes tuning the antenna based on the digitized power detectionsignal.

In some embodiments, the power detector is a root mean square powerdetector.

In various embodiments, the combiner is a quadrature hybrid. Accordingto several embodiments, the quadrature hybrid includes a first terminalelectrically connected to the first end of the coupled line, a secondterminal electrically connected to the second end of the coupled line, athird terminal configured to output the combined signal, and a fourthterminal electrically connected to a termination impedance.

In a number of embodiments, the directional coupler has a couplingfactor of at least 16 dB.

In various embodiments, the directional coupler has a directivity of atleast 10 dB.

In some embodiments, the directional coupler is implemented as a slowwave coupler.

In several embodiments, the through line is substantially U-shaped andthe coupled line is substantially U-shaped.

In a number of embodiments, the method further includes outputting thefirst coupled signal to the combiner from a first switch output in afirst state of a switch, and outputting the first coupled signal at asecond switch output in a second state of the switch.

In some embodiments, the amplified radio frequency signal is amillimeter wave signal.

In certain embodiments, the present disclosure relates to a packagedmodule. The packaged module includes a package substrate and at leastone semiconductor die attached to the package substrate. The at leastone semiconductor die includes a directional coupler having a throughline and a coupled line, a combiner configured to generated a combinedsignal based on combining a first coupled signal from a first end of thecoupled line and a second coupled signal from a second end of thecoupled line, and a power detector configured to generate a powerdetection signal based on detecting a power of the combined signal.

In various embodiments, the packaged module further includes a poweramplifier configured to provide an amplified radio frequency signal tothe through line. In a number of embodiments, the power amplifier andthe directional coupler are on a common semiconductor die of the atleast one semiconductor die. In several embodiments, the power amplifierand the directional coupler are on different semiconductor dies of theat least one semiconductor die. According to various embodiments, thepackaged module further includes an antenna, the through lineelectrically connected between an output of the power amplifier and theantenna.

In a number of embodiments, the at least one semiconductor die furtherincludes an analog-to-digital converter configured to digitize the powerdetection signal.

In several embodiments, the power detector is a root mean square powerdetector.

In various embodiments, the combiner is a quadrature hybrid.

In some embodiments, the directional coupler has a coupling factor of atleast 16 dB.

In a number of embodiments, the directional coupler has a directivity ofat least 10 dB.

In various embodiments, the directional coupler is implemented as a slowwave coupler.

In some embodiments, the through line is substantially U-shaped and thecoupled line is substantially U-shaped. According to variousembodiments, the directional coupler further includes a plurality ofcoupling conductors extending beneath the through line and the coupledline.

In several embodiments, the at least one semiconductor die furtherincludes a switch including an input electrically connected to the firstend of the coupled line, a first output configured to provide the firstcoupled signal to the combiner in a first state of the switch, and asecond output configured to output a forward power signal in a secondstate of the switch.

In a number of embodiments, the amplified radio frequency signal is amillimeter wave signal.

In certain embodiments, the present disclosure relates to a mobiledevice. The mobile device includes a transceiver configured to output aradio frequency signal, an antenna, and a front end system configured toprocess the radio frequency signal to generate an amplified radiofrequency signal for transmission on the antenna. The front end systemincludes a power amplifier configured amplify the radio frequency signaland a directional coupler having a through line and a coupled line, thethrough line electrically connected between an output of the poweramplifier and the antenna, the front end system further including acombiner configured to generated a combined signal based on combining afirst coupled signal from a first end of the coupled line and a secondcoupled signal from a second end of the coupled line.

In a number of embodiments, the front end system further includes apower detector configured to generate a power detection signal based ondetecting a power of the combined signal. According to severalembodiments, the front end system further includes an analog-to-digitalconverter configured to digitize the power detection signal. Inaccordance with some embodiments, the mobile device further includes abaseband processor configured to process the digitized power detectionsignal to control a transmit power of the mobile device. According toseveral embodiments, the baseband processor is configured to tune anoutput matching network of the power amplifier based on the digitizedpower detection signal. In accordance with some embodiments, thebaseband processor is configured to adjust a bias of the power amplifierbased on the digitized power detection signal. According to variousembodiments, the baseband processor is configured to tune the antennabased on the digitized power detection signal.

In some embodiments, the power detector is a root mean square powerdetector.

In various embodiments, the combiner is a quadrature hybrid. Accordingto a number of embodiments, the front end system further includes atermination impedance, and the quadrature hybrid includes a firstterminal electrically connected to the first end of the coupled line, asecond terminal electrically connected to the second end of the coupledline, a third terminal configured to output the combined signal, and afourth terminal electrically connected to the termination impedance.

In several embodiments, the directional coupler has a coupling factor ofat least 16 dB.

In a number of embodiments, the directional coupler has a directivity ofat least 10 dB.

In various embodiments, the directional coupler is implemented as a slowwave coupler.

In some embodiments, the through line is substantially U-shaped and thecoupled line is substantially U-shaped. According to severalembodiments, the directional coupler further includes a plurality ofcoupling conductors extending beneath the through line and the coupledline.

In a number of embodiments, the front end system further includes aswitch includes an input electrically connected to the first end of thecoupled line, a first output configured to provide the first coupledsignal to the combiner in a first state of the switch, and a secondoutput configured to output a forward power signal in a second state ofthe switch.

In various embodiments, the amplified radio frequency signal is amillimeter wave signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will now be described, by way ofnon-limiting example, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of one example of a communication network.

FIG. 2A is a schematic diagram of one example of a downlink channelusing multi-input and multi-output (MIMO) communications.

FIG. 2B is schematic diagram of one example of an uplink channel usingMIMO communications.

FIG. 2C is schematic diagram of another example of an uplink channelusing MIMO communications.

FIG. 3A is a schematic diagram of one example of a communication systemthat operates with beamforming.

FIG. 3B is a schematic diagram of one example of beamforming to providea transmit beam.

FIG. 3C is a schematic diagram of one example of beamforming to providea receive beam.

FIG. 4A is a schematic diagram of a power amplifier system according toone embodiment.

FIG. 4B is a schematic diagram of a power amplifier system according toanother embodiment.

FIG. 5 is a schematic diagram of a power amplifier system according toanother embodiment.

FIG. 6 is a schematic diagram of a power amplifier system according toanother embodiment.

FIG. 7A is a graph of one example of load power versus load phase.

FIG. 7B is a graph of one example of load power and true power detectoroutput versus load phase.

FIG. 8A is a graph of another example of load power and true powerdetector output versus load phase.

FIG. 8B is a graph of one example of load power and true power detectoroutput versus load phase.

FIG. 9 is a schematic diagram of one embodiment of a mobile device.

FIG. 10A is a schematic diagram of one embodiment of a packaged module.

FIG. 10B is a schematic diagram of a cross-section of the packagedmodule of FIG. 10A taken along the lines 10B-10B.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following detailed description of certain embodiments presentsvarious descriptions of specific embodiments. However, the innovationsdescribed herein can be embodied in a multitude of different ways, forexample, as defined and covered by the claims. In this description,reference is made to the drawings where like reference numerals canindicate identical or functionally similar elements. It will beunderstood that elements illustrated in the figures are not necessarilydrawn to scale. Moreover, it will be understood that certain embodimentscan include more elements than illustrated in a drawing and/or a subsetof the elements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings.

The International Telecommunication Union (ITU) is a specialized agencyof the United Nations (UN) responsible for global issues concerninginformation and communication technologies, including the shared globaluse of radio spectrum.

The 3rd Generation Partnership Project (3GPP) is a collaboration betweengroups of telecommunications standard bodies across the world, such asthe Association of Radio Industries and Businesses (ARIB), theTelecommunications Technology Committee (TTC), the China CommunicationsStandards Association (CCSA), the Alliance for TelecommunicationsIndustry Solutions (ATIS), the Telecommunications Technology Association(TTA), the European Telecommunications Standards Institute (ETSI), andthe Telecommunications Standards Development Society, India (TSDSI).

Working within the scope of the ITU, 3GPP develops and maintainstechnical specifications for a variety of mobile communicationtechnologies, including, for example, second generation (2G) technology(for instance, Global System for Mobile Communications (GSM) andEnhanced Data Rates for GSM Evolution (EDGE)), third generation (3G)technology (for instance, Universal Mobile Telecommunications System(UMTS) and High Speed Packet Access (HSPA)), and fourth generation (4G)technology (for instance, Long Term Evolution (LTE) and LTE-Advanced).

The technical specifications controlled by 3GPP can be expanded andrevised by specification releases, which can span multiple years andspecify a breadth of new features and evolutions.

In one example, 3GPP introduced carrier aggregation (CA) for LTE inRelease 10. Although initially introduced with two downlink carriers,3GPP expanded carrier aggregation in Release 14 to include up to fivedownlink carriers and up to three uplink carriers. Other examples of newfeatures and evolutions provided by 3GPP releases include, but are notlimited to, License Assisted Access (LAA), enhanced LAA (eLAA),Narrowband Internet of things (NB-IOT), Vehicle-to-Everything (V2X), andHigh Power User Equipment (HPUE).

3GPP introduced Phase 1 of fifth generation (5G) technology in Release15, and plans to introduce Phase 2 of 5G technology in Release 16(targeted for 2019). Subsequent 3GPP releases will further evolve andexpand 5G technology. 5G technology is also referred to herein as 5G NewRadio (NR).

5G NR supports or plans to support a variety of features, such ascommunications over millimeter wave spectrum, beamforming capability,high spectral efficiency waveforms, low latency communications, multipleradio numerology, and/or non-orthogonal multiple access (NOMA). Althoughsuch RF functionalities offer flexibility to networks and enhance userdata rates, supporting such features can pose a number of technicalchallenges.

The teachings herein are applicable to a wide variety of communicationsystems, including, but not limited to, communication systems usingadvanced cellular technologies, such as LTE-Advanced, LTE-Advanced Pro,and/or 5G NR.

FIG. 1 is a schematic diagram of one example of a communication network10. The communication network 10 includes a macro cell base station 1, asmall cell base station 3, and various examples of user equipment (UE),including a first mobile device 2 a, a wireless-connected car 2 b, alaptop 2 c, a stationary wireless device 2 d, a wireless-connected train2 e, a second mobile device 2 f, and a third mobile device 2 g.

Although specific examples of base stations and user equipment areillustrated in FIG. 1 , a communication network can include basestations and user equipment of a wide variety of types and/or numbers.

For instance, in the example shown, the communication network 10includes the macro cell base station 1 and the small cell base station3. The small cell base station 3 can operate with relatively lowerpower, shorter range, and/or with fewer concurrent users relative to themacro cell base station 1. The small cell base station 3 can also bereferred to as a femtocell, a picocell, or a microcell. Although thecommunication network 10 is illustrated as including two base stations,the communication network 10 can be implemented to include more or fewerbase stations and/or base stations of other types.

Although various examples of user equipment are shown, the teachingsherein are applicable to a wide variety of user equipment, including,but not limited to, mobile phones, tablets, laptops, IoT devices,wearable electronics, customer premises equipment (CPE),wireless-connected vehicles, wireless relays, and/or a wide variety ofother communication devices. Furthermore, user equipment includes notonly currently available communication devices that operate in acellular network, but also subsequently developed communication devicesthat will be readily implementable with the inventive systems,processes, methods, and devices as described and claimed herein.

The illustrated communication network 10 of FIG. 1 supportscommunications using a variety of cellular technologies, including, forexample, 4G LTE and 5G NR. In certain implementations, the communicationnetwork 10 is further adapted to provide a wireless local area network(WLAN), such as WiFi. Although various examples of communicationtechnologies have been provided, the communication network 10 can beadapted to support a wide variety of communication technologies.

Various communication links of the communication network 10 have beendepicted in FIG. 1 . The communication links can be duplexed in a widevariety of ways, including, for example, using frequency-divisionduplexing (FDD) and/or time-division duplexing (TDD). FDD is a type ofradio frequency communications that uses different frequencies fortransmitting and receiving signals. FDD can provide a number ofadvantages, such as high data rates and low latency. In contrast, TDD isa type of radio frequency communications that uses about the samefrequency for transmitting and receiving signals, and in which transmitand receive communications are switched in time. TDD can provide anumber of advantages, such as efficient use of spectrum and variableallocation of throughput between transmit and receive directions.

In certain implementations, user equipment can communicate with a basestation using one or more of 4G LTE, 5G NR, and WiFi technologies. Incertain implementations, enhanced license assisted access (eLAA) is usedto aggregate one or more licensed frequency carriers (for instance,licensed 4G LTE and/or 5G NR frequencies), with one or more unlicensedcarriers (for instance, unlicensed WiFi frequencies).

As shown in FIG. 1 , the communication links include not onlycommunication links between UE and base stations, but also UE to UEcommunications and base station to base station communications. Forexample, the communication network 10 can be implemented to supportself-fronthaul and/or self-backhaul (for instance, as between mobiledevice 2 g and mobile device 2 f).

The communication links can operate over a wide variety of frequencies.In certain implementations, communications are supported using 5G NRtechnology over one or more frequency bands that are less than 6Gigahertz (GHz) and/or over one or more frequency bands that are greaterthan 6 GHz. For example, the communication links can serve FrequencyRange 1 (FR1), Frequency Range 2 (FR2), or a combination thereof. In oneembodiment, one or more of the mobile devices support a HPUE power classspecification.

In certain implementations, a base station and/or user equipmentcommunicates using beamforming. For example, beamforming can be used tofocus signal strength to overcome path losses, such as high lossassociated with communicating over high signal frequencies. In certainembodiments, user equipment, such as one or more mobile phones,communicate using beamforming on millimeter wave frequency bands in therange of 30 GHz to 300 GHz and/or upper centimeter wave frequencies inthe range of 6 GHz to 30 GHz, or more particularly, 24 GHz to 30 GHz.

Different users of the communication network 10 can share availablenetwork resources, such as available frequency spectrum, in a widevariety of ways.

In one example, frequency division multiple access (FDMA) is used todivide a frequency band into multiple frequency carriers. Additionally,one or more carriers are allocated to a particular user. Examples ofFDMA include, but are not limited to, single carrier FDMA (SC-FDMA) andorthogonal FDMA (OFDMA). OFDMA is a multicarrier technology thatsubdivides the available bandwidth into multiple mutually orthogonalnarrowband subcarriers, which can be separately assigned to differentusers.

Other examples of shared access include, but are not limited to, timedivision multiple access (TDMA) in which a user is allocated particulartime slots for using a frequency resource, code division multiple access(CDMA) in which a frequency resource is shared amongst different usersby assigning each user a unique code, space-divisional multiple access(SDMA) in which beamforming is used to provide shared access by spatialdivision, and non-orthogonal multiple access (NOMA) in which the powerdomain is used for multiple access. For example, NOMA can be used toserve multiple users at the same frequency, time, and/or code, but withdifferent power levels.

Enhanced mobile broadband (eMBB) refers to technology for growing systemcapacity of LTE networks. For example, eMBB can refer to communicationswith a peak data rate of at least 10 Gbps and a minimum of 100 Mbps foreach user. Ultra-reliable low latency communications (uRLLC) refers totechnology for communication with very low latency, for instance, lessthan 2 milliseconds. uRLLC can be used for mission-criticalcommunications such as for autonomous driving and/or remote surgeryapplications. Massive machine-type communications (mMTC) refers to lowcost and low data rate communications associated with wirelessconnections to everyday objects, such as those associated with Internetof Things (IoT) applications.

The communication network 10 of FIG. 1 can be used to support a widevariety of advanced communication features, including, but not limitedto, eMBB, uRLLC, and/or mMTC.

FIG. 2A is a schematic diagram of one example of a downlink channelusing multi-input and multi-output (MIMO) communications. FIG. 2B isschematic diagram of one example of an uplink channel using MIMOcommunications.

MIMO communications use multiple antennas for simultaneouslycommunicating multiple data streams over common frequency spectrum. Incertain implementations, the data streams operate with differentreference signals to enhance data reception at the receiver. MIMOcommunications benefit from higher SNR, improved coding, and/or reducedsignal interference due to spatial multiplexing differences of the radioenvironment.

MIMO order refers to a number of separate data streams sent or received.For instance, MIMO order for downlink communications can be described bya number of transmit antennas of a base station and a number of receiveantennas for UE, such as a mobile device. For example, two-by-two (2×2)DL MIMO refers to MIMO downlink communications using two base stationantennas and two UE antennas. Additionally, four-by-four (4×4) DL MIMOrefers to MIMO downlink communications using four base station antennasand four UE antennas.

In the example shown in FIG. 2A, downlink MIMO communications areprovided by transmitting using M antennas 43 a, 43 b, 43 c, . . . 43 mof the base station 41 and receiving using N antennas 44 a, 44 b, 44 c,. . . 44 n of the mobile device 42. Accordingly, FIG. 2A illustrates anexample of m×n DL MIMO.

Likewise, MIMO order for uplink communications can be described by anumber of transmit antennas of UE, such as a mobile device, and a numberof receive antennas of a base station. For example, 2×2 UL MIMO refersto MIMO uplink communications using two UE antennas and two base stationantennas. Additionally, 4×4 UL MIMO refers to MIMO uplink communicationsusing four UE antennas and four base station antennas.

In the example shown in FIG. 2B, uplink MIMO communications are providedby transmitting using N antennas 44 a, 44 b, 44 c, . . . 44 n of themobile device 42 and receiving using M antennas 43 a, 43 b, 43 c, . . .43 m of the base station 41. Accordingly, FIG. 2B illustrates an exampleof n×m UL MIMO.

By increasing the level or order of MIMO, bandwidth of an uplink channeland/or a downlink channel can be increased.

MIMO communications are applicable to communication links of a varietyof types, such as FDD communication links and TDD communication links.

FIG. 2C is schematic diagram of another example of an uplink channelusing MIMO communications. In the example shown in FIG. 2C, uplink MIMOcommunications are provided by transmitting using N antennas 44 a, 44 b,44 c, . . . 44 n of the mobile device 42. Additional a first portion ofthe uplink transmissions are received using M antennas 43 a 1, 43 b 1,43 c 1, . . . 43 m 1 of a first base station 41 a, while a secondportion of the uplink transmissions are received using M antennas 43 a2, 43 b 2, 43 c 2, . . . 43 m 2 of a second base station 41 b.Additionally, the first base station 41 a and the second base station 41b communication with one another over wired, optical, and/or wirelesslinks.

The MIMO scenario of FIG. 2C illustrates an example in which multiplebase stations cooperate to facilitate MIMO communications.

FIG. 3A is a schematic diagram of one example of a communication system110 that operates with beamforming. The communication system 110includes a transceiver 105, signal conditioning circuits 104 a 1, 104 a2 . . . 104 an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1, 104 m 2 . . .104 mn, and an antenna array 102 that includes antenna elements 103 a 1,103 a 2 . . . 103 an, 103 b 1, 103 b 2 . . . 103 bn, 103 m 1, 103 m 2 .. . 103 mn.

Communications systems that communicate using millimeter wave carriers(for instance, 30 GHz to 300 GHz), centimeter wave carriers (forinstance, 3 GHz to 30 GHz), and/or other frequency carriers can employan antenna array to provide beam formation and directivity fortransmission and/or reception of signals.

For example, in the illustrated embodiment, the communication system 110includes an array 102 of m×n antenna elements, which are each controlledby a separate signal conditioning circuit, in this embodiment. Asindicated by the ellipses, the communication system 110 can beimplemented with any suitable number of antenna elements and signalconditioning circuits.

With respect to signal transmission, the signal conditioning circuitscan provide transmit signals to the antenna array 102 such that signalsradiated from the antenna elements combine using constructive anddestructive interference to generate an aggregate transmit signalexhibiting beam-like qualities with more signal strength propagating ina given direction away from the antenna array 102.

In the context of signal reception, the signal conditioning circuitsprocess the received signals (for instance, by separately controllingreceived signal phases) such that more signal energy is received whenthe signal is arriving at the antenna array 102 from a particulardirection. Accordingly, the communication system 110 also providesdirectivity for reception of signals.

The relative concentration of signal energy into a transmit beam or areceive beam can be enhanced by increasing the size of the array. Forexample, with more signal energy focused into a transmit beam, thesignal is able to propagate for a longer range while providingsufficient signal level for RF communications. For instance, a signalwith a large proportion of signal energy focused into the transmit beamcan exhibit high effective isotropic radiated power (EIRP).

In the illustrated embodiment, the transceiver 105 provides transmitsignals to the signal conditioning circuits and processes signalsreceived from the signal conditioning circuits. As shown in FIG. 3A, thetransceiver 105 generates control signals for the signal conditioningcircuits. The control signals can be used for a variety of functions,such as controlling the gain and phase of transmitted and/or receivedsignals to control beamforming.

FIG. 3B is a schematic diagram of one example of beamforming to providea transmit beam. FIG. 3B illustrates a portion of a communication systemincluding a first signal conditioning circuit 114 a, a second signalconditioning circuit 114 b, a first antenna element 113 a, and a secondantenna element 113 b.

Although illustrated as included two antenna elements and two signalconditioning circuits, a communication system can include additionalantenna elements and/or signal conditioning circuits. For example, FIG.3B illustrates one embodiment of a portion of the communication system110 of FIG. 3A.

The first signal conditioning circuit 114 a includes a first phaseshifter 130 a, a first power amplifier 131 a, a first low noiseamplifier (LNA) 132 a, and switches for controlling selection of thepower amplifier 131 a or LNA 132 a. Additionally, the second signalconditioning circuit 114 b includes a second phase shifter 130 b, asecond power amplifier 131 b, a second LNA 132 b, and switches forcontrolling selection of the power amplifier 131 b or LNA 132 b.

Although one embodiment of signal conditioning circuits is shown, otherimplementations of signal conditioning circuits are possible. Forinstance, in one example, a signal conditioning circuit includes one ormore band filters, duplexers, and/or other components.

In the illustrated embodiment, the first antenna element 113 a and thesecond antenna element 113 b are separated by a distance d.Additionally, FIG. 3B has been annotated with an angle θ, which in thisexample has a value of about 90° when the transmit beam direction issubstantially perpendicular to a plane of the antenna array and a valueof about 0° when the transmit beam direction is substantially parallelto the plane of the antenna array.

By controlling the relative phase of the transmit signals provided tothe antenna elements 113 a, 113 b, a desired transmit beam angle θ canbe achieved. For example, when the first phase shifter 130 a has areference value of 0°, the second phase shifter 130 b can be controlledto provide a phase shift of about −2πf(d/ν)cos θ radians, where f is thefundamental frequency of the transmit signal, d is the distance betweenthe antenna elements, ν is the velocity of the radiated wave, and π isthe mathematic constant pi.

In certain implementations, the distance d is implemented to be about½λ, where λ is the wavelength of the fundamental component of thetransmit signal. In such implementations, the second phase shifter 130 bcan be controlled to provide a phase shift of about −π cos θ radians toachieve a transmit beam angle θ.

Accordingly, the relative phase of the phase shifters 130 a, 130 b canbe controlled to provide transmit beamforming. In certainimplementations, a baseband processor and/or a transceiver (for example,the transceiver 105 of FIG. 3A) controls phase values of one or morephase shifters and gain values of one or more controllable amplifiers tocontrol beamforming.

FIG. 3C is a schematic diagram of one example of beamforming to providea receive beam. FIG. 3C is similar to FIG. 3B, except that FIG. 3Cillustrates beamforming in the context of a receive beam rather than atransmit beam.

As shown in FIG. 3C, a relative phase difference between the first phaseshifter 130 a and the second phase shifter 130 b can be selected toabout equal to −2πf(d/ν)cos θ radians to achieve a desired receive beamangle θ. In implementations in which the distance d corresponds to about½λ, the phase difference can be selected to about equal to −π cos θradians to achieve a receive beam angle θ.

Although various equations for phase values to provide beamforming havebeen provided, other phase selection values are possible, such as phasevalues selected based on implementation of an antenna array,implementation of signal conditioning circuits, and/or a radioenvironment.

Examples of Radio Frequency Systems with True Power Detection

In certain applications, such as wideband and/or high frequencycommunications, it is important to know an amount of true powerdelivered to an antenna. For example, information indicating an amountof actual power can be processed to provide enhanced control overtransmit power, linearity, and/or other transmission characteristics.

A power measurement can be used to enhance a performance of an RFsystem. Examples of mechanisms for controlling power delivered to anantenna include, but are not limited to, tuning of a power amplifier'soutput matching network, adjusting a power amplifier's bias, and/ortuning of an antenna (for instance, aperture tuning).

When a standing wave ratio (SWR) of a load is not matched, the powerdetected at the output of a power amplifier drops. Additionally, a totalradiated power (TRP), effective isotropic radiated power (EIRP), and/orsystem efficiency is reduced.

It is desirable to detect the true power delivered from the poweramplifier to a load, such that one or more adjustment mechanisms can beused to deliver a desired amount of power to an antenna.

Conventional power detectors fail to measure true power delivered to aload/antenna over a wide range of SWR conditions, particularly formillimeter wave frequencies.

For example, a forward or incident power and a reverse or reflectedpower can be measured using a directional coupler and a pair of powerdetectors. Although such a power measurement technique can be used todetect a standing wave ratio, true power delivered depends on thecomplex impedance of the load, and thus also on load phase. Although aworst case phase can be used as a conservative estimate for actual powerdelivered, assuming the worst case phase can lead to inefficienciesand/or an overdesigned system.

Apparatus and methods for true power detection are provided herein. Incertain embodiments, a power amplifier system includes an antenna, adirectional coupler, and a power amplifier electrically connected to theantenna by way of a through line of the directional coupler. The poweramplifier system further includes a combiner that combines a firstcoupled signal from a first end of the directional coupler's coupledline with a second coupled signal from a second end of the directionalcoupler's coupled line.

The first coupled signal and the second coupled signal includeinformation indicating a load phase, and thus the output of the combinercan be processed to generate a detection signal indicating true power.In certain implementations, the power amplifier system includes a powerdetector (for instance, a root mean square or RMS power detector) thatgenerates a true power detection signal based on detecting an amount ofpower at the output of the combiner. In certain implementations, thecombiner is implemented as a quadrature combiner, such as a quadraturehybrid (for instance, a branch line or lumped element equivalentcombiner).

The directional coupler includes a through line and a coupled line,which are electromagnetically coupled to one another. In certainimplementations the through line and the coupled line are coupled with acoupling factor of at least 16 dB. For example, the directional couplercan be implemented as a slow wave coupler.

True power detection systems can be used in a wide variety ofapplications. For example, true power detection systems can be used fortrue power detection of radio frequency (RF) signals transmitted by basestations, network access points, mobile phones, tablets, laptops,computers, and/or other communications devices. Furthermore,communications devices that utilize millimeter wave carriers (forinstance, 30 GHz to 300 GHz), centimeter wave carriers (for instance, 3GHz to 30 GHz), and/or other carrier frequencies can employ a true powerdetection system for detecting the true power delivered to an antenna.

FIG. 4A is a schematic diagram of a power amplifier system 215 accordingto one embodiment. The power amplifier system 215 includes a poweramplifier 201, an antenna 202, and a true power detection system 205.The true power detection system 205 includes a directional coupler 211,a combiner 212, and a power detector 213.

The true power detection system 205 serves to generate a true powerdetection signal (DET) indicating a true or actual power delivered tothe antenna 202 by the power amplifier 201.

Although conventional power measurement techniques can be used to detecta standing wave ratio, true power delivered depends on the load compleximpedance, and thus also on load phase. Although a worst case phase canbe used as a conservative estimate for actual power delivered, assumingthe worst case phase can lead to inefficiencies and/or an overdesignedsystem.

In contrast, the true power detection signal changes in relation to loadphase of the antenna 202. Accordingly, an actual amount of powerdelivered to the antenna 202 can be detected.

In the illustrated embodiment, the true power detection system 205includes a directional coupler 211, a combiner 212, and a power detector213 that outputs the true power detection signal. The directionalcoupler 211 includes a through line that is positioned along an RFsignal path from an output of the power amplifier 201 to the antenna202. As indicated by the ellipses, one or more components can beincluded between the power amplifier's output and the through lineand/or between the through line and the antenna 202.

The combiner 212 operates to combine a first coupled signal from one endof the directional coupler's coupled line with a second coupled signalfrom another end of the directional coupler's coupled line. The powerdetector 213 generates the true power detection signal based ondetecting an amount of power of the combined signal generated by thecombiner 212.

FIG. 4B is a schematic diagram of a power amplifier system 220 accordingto another embodiment. The power amplifier system 220 of FIG. 4Bincludes a power amplifier 201, an antenna 202, a true power detectionsystem 216, and a termination impedance 219.

The true power detection system 216 of FIG. 4B is similar to the truepower detection system 205 of FIG. 4A, except that the true powerdetection system 216 of FIG. 4B further includes a first switch 217 anda second switch 218. The state of the first switch 217 and the secondswitch 218 can be controlled in a wide variety of ways, such as by acontrol signal from a radio frequency integrated circuit (RF IC),baseband processor, and/or other suitable circuitry.

As shown in FIG. 4B, the first switch 217 and the second switch 218 canbe set in a first state in which the coupled line of the directionalcoupler 211 is actively connected to the combiner 212 such that the truepower detection signal (DET) is generated. The first switch 217 and thesecond switch 218 can also be set in a second state in which one end ofthe coupled line of the directional coupler 217 is actively connected tothe termination impedance 219 (for instance, a resistor of about 50Ohms) and the other end of the coupled line of the directional coupler217 generates a forward power detection signal (FPWR).

Implementing the true power detection system 216 with switches enhancesflexibility by allowing the directional coupler 211 to be used for bothtrue power detection and for forward power detection.

FIG. 5 is a schematic diagram of a power amplifier system 240 accordingto another embodiment. The illustrated power amplifier system 240includes a baseband processor 221, an I/Q modulator 234, a poweramplifier (PA) 235, front-end antenna access circuitry 225, an antenna226, a PA bias control circuit 227, a PA supply control circuit 228, ananalog-to-digital converter (ADC) 239, and a true power detection system205.

Although the power amplifier system 240 of FIG. 5 is depicted asincluding the true power detection system 205 of FIG. 4A, the poweramplifier system 240 can be implemented with any of the true powerdetection systems disclosed herein.

The baseband processor 221 can be used to generate an in-phase (I)signal and a quadrature-phase (Q) signal, which can be used to representa sinusoidal wave or signal of a desired amplitude, frequency, andphase. For example, the I signal can be used to represent an in-phasecomponent of the sinusoidal wave and the Q signal can be used torepresent a quadrature-phase component of the sinusoidal wave, which canbe an equivalent representation of the sinusoidal wave. In certainimplementations, the I and Q signals can be provided to the I/Qmodulator 234 in a digital format. The baseband processor 221 can be anysuitable processor configured to process a baseband signal. Forinstance, the baseband processor 221 can include a digital signalprocessor, a microprocessor, a programmable core, or any combinationthereof. Moreover, in some implementations, two or more basebandprocessors 221 can be included in the power amplifier system 240.

The I/Q modulator 234 can be configured to receive the I and Q signalsfrom the baseband processor 221 and to process the I and Q signals togenerate an RF signal. For example, the I/Q modulator 234 can includedigital-to-analog converters (DACs) configured to convert the I and Qsignals into an analog format, mixers for upconverting the I and Qsignals to RF, and a signal combiner for combining the upconverted I andQ signals into an RF signal suitable for amplification by the poweramplifier 235. In certain implementations, the I/Q modulator 234 caninclude one or more filters configured to filter frequency content ofsignals processed therein.

The power amplifier 235 can receive the RF signal from the I/Q modulator234, and when enabled can provide an amplified RF signal to the antenna226 via the front-end antenna access circuitry 225.

The front-end antenna access circuitry 225 can be implemented in a widevariety of ways. In one example, the front-end antenna access circuitry225 includes one or more switches, filters, duplexers, multiplexers,and/or other components. In another example, the front-end antennaaccess circuitry 225 is omitted in favor of the power amplifier 235providing the amplified RF signal directly to the antenna 226.

The true power detection system 205 includes a directional coupler 211,a combiner 212, and a power detector 213. The directional coupler 211provides a first coupled signal and a second coupled signal to thecombiner 212. Additionally, the power detector 213 detects an amount ofpower in the combined signal from the combiner 212 to thereby generate atrue power detection signal.

The true power detection signal is provided to the ADC 239, whichconverts the true power detection signal to a digital format suitablefor processing by the baseband processor 221. Implementing the poweramplifier system 240 with true power detection can provide a number ofadvantages. For example, the baseband processor 221 can process thedigital true power detection signal to provide power control, tocompensate for transmitter impairments, and/or to perform digitalpre-distortion (DPD).

The PA supply control circuit 228 receives a power control signal fromthe baseband processor 221, and controls supply voltages of the poweramplifier 235. In the illustrated configuration, the PA supply controlcircuit 228 generates a first supply voltage V_(CC1) for powering aninput stage of the power amplifier 235 and a second supply voltageV_(CC2) for powering an output stage of the power amplifier 235. The PAsupply control circuit 228 can control the voltage level of the firstsupply voltage V_(CC1) and/or the second supply voltage V_(CC2) toenhance the power amplifier system's PAE.

The PA supply control circuit 228 can employ various power managementtechniques to change the voltage level of one or more of the supplyvoltages over time to improve the power amplifier's power addedefficiency (PAE), thereby reducing power dissipation.

One technique for improving efficiency of a power amplifier is averagepower tracking (APT), in which a DC-to-DC converter is used to generatea supply voltage for a power amplifier based on the power amplifier'saverage output power. Another technique for improving efficiency of apower amplifier is envelope tracking (ET), in which a supply voltage ofthe power amplifier is controlled in relation to the envelope of the RFsignal. Thus, when a voltage level of the envelope of the RF signalincreases the voltage level of the power amplifier's supply voltage canbe increased. Likewise, when the voltage level of the envelope of the RFsignal decreases the voltage level of the power amplifier's supplyvoltage can be decreased to reduce power consumption.

In certain configurations, the PA supply control circuit 228 is amulti-mode supply control circuit that can operate in multiple supplycontrol modes including an APT mode and an ET mode. For example, thepower control signal from the baseband processor 221 can instruct the PAsupply control circuit 228 to operate in a particular supply controlmode.

As shown in FIG. 5 , the PA bias control circuit 227 receives a biascontrol signal from the baseband processor 221, and generates biascontrol signals for the power amplifier 235. In the illustratedconfiguration, the bias control circuit 227 generates bias controlsignals for both an input stage of the power amplifier 235 and an outputstage of the power amplifier 235. However, other implementations arepossible.

FIG. 6 is a schematic diagram of a power amplifier system 320 accordingto another embodiment. The power amplifier system 320 includes a poweramplifier 301, an antenna 302 (implemented as a patch antenna, in thisembodiment), a directional coupler, a quadrature hybrid 308, a powerdetector 309, and a termination impedance 310. In the illustratedembodiment, the directional coupler is implemented as a slow wavecoupler including a through line 303, a coupled line 304, a first groundplane 305, a second ground plane 306, and coupling conductors 311.

Although one embodiment of a power amplifier system with true powerdetection is depicted, the teachings herein are applicable to poweramplifier systems implemented in a wide variety of ways. For example, apower amplifier system can include power amplifiers, antennas,directional couplers, combiners, and/or power detectors implemented inother ways. Accordingly, other implementations are possible.

In the illustrated embodiment, the through line 303 is substantiallyU-shaped, with a first end of the through line 303 connected to anoutput of the power amplifier 301 and a second end of the through line303 connected to the antenna 302. Additionally, the coupled line 304 issubstantially U-shaped, with a first end of the coupled line 304connected to a first terminal of the quadrature hybrid 308 and a secondend of the coupled line 304 connected to a second terminal of thequadrature hybrid 308. In certain implementations, the first terminal ofthe quadrature hybrid 308 receives a −3 dB coupled signal at about 0degrees and the second terminal of the quadrature hybrid 308 receives a−3 dB coupled signal at about −90 degrees. The quadrature hybrid 308further includes a third terminal that outputs a combined signal(V_(out)) and a fourth terminal coupled to the termination resistor 310.The power detector 309 detects a power of the combined signal togenerate a true power detection signal.

In the illustrated embodiment, the power amplifier system 320 includesthe first ground plane 305 and the second ground plane 306, which areseparated from one another by a gap. Additionally, the through line 303is routed over the gap, and the coupled line 304 is routed over thesecond ground plane 306. However, other implementations are possible,such as configurations including a common ground plane extending beneaththe through line 303 and the coupled line 304.

As shown in FIG. 6 , the coupling conductors 311 are included to enhancea coupling factor of the slow wave coupler. For example, in certainimplementations the slow wave coupler has a coupling factor of at least16 dB and/or a directivity of at least 10 dB.

FIG. 7A is a graph of one example of load power versus load phase. Thegraph includes a first plot 701 for standing wave ratio (SWR) of 2, anda second plot 702 for SWR of 3.

As shown in FIG. 7A, load power varies with load phase and with SWR.Thus, the ratio of reflected to incident power alone cannot be used todetect true power. For example, two different SWRs have the same powerdelivered to the load at certain load phases.

FIG. 7B is a graph of one example of load power and true power detectoroutput versus load phase. The graph includes a first plot 703 of loadpower in dBm and a second plot 704 of true power detector output in dB.

As shown in FIG. 7B, the true power detector output changes in relationto load power, even as load phase changes. For example, in certainimplementations herein a true power detector signal changes in relationto V_(ref)−j*V_(inc), wherein j is the imaginary unit, V_(ref) is thereflected voltage, and V_(inc) is the incident voltage.

FIG. 8A is a graph of another example of load power and true powerdetector output versus load phase. The graph includes a first plot 705of load power in dBm, and a second plot 706 of true power detectoroutput in dB. The graph corresponds to example results for SWR of 2.

FIG. 8B is a graph of one example of load power and true power detectoroutput versus load phase. The graph includes a first plot 707 of loadpower in dBm, and a second plot 708 of true power detector output in dB.The graph corresponds to example results for SWR of 3.

Although various example of simulation results are depicted in FIGS.7A-8B, simulation results can vary based on a wide variety of factors,including, but not limited to, simulation parameters (includingoperating frequency), antenna models, and/or simulation tools.

FIG. 9 is a schematic diagram of one embodiment of a mobile device 800.The mobile device 800 includes a baseband system 801, a transceiver 802,a front end system 803, antennas 804, a power management system 805, amemory 806, a user interface 807, and a battery 808.

The mobile device 800 can be used communicate using a wide variety ofcommunications technologies, including, but not limited to, 2G, 3G, 4G(including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (forinstance, Wi-Fi), WPAN (for instance, Bluetooth and ZigBee), WMAN (forinstance, WiMax), and/or GPS technologies.

The transceiver 802 generates RF signals for transmission and processesincoming RF signals received from the antennas 804. It will beunderstood that various functionalities associated with the transmissionand receiving of RF signals can be achieved by one or more componentsthat are collectively represented in FIG. 9 as the transceiver 802. Inone example, separate components (for instance, separate circuits ordies) can be provided for handling certain types of RF signals.

The front end system 803 aids is conditioning signals transmitted toand/or received from the antennas 804. In the illustrated embodiment,the front end system 803 includes a true power detection system 810,power amplifiers (PAs) 811, low noise amplifiers (LNAs) 812, filters813, switches 814, and duplexers 815. The true power detection system810 can be implemented in accordance with any of the embodiments herein.

Although certain components are depicted in the front end system 803,other implementations are possible. For example, the front end system803 can provide a number of functionalities, including, but not limitedto, amplifying signals for transmission, amplifying received signals,filtering signals, switching between different bands, switching betweendifferent power modes, switching between transmission and receivingmodes, duplexing of signals, multiplexing of signals (for instance,diplexing or triplexing), or some combination thereof.

In certain implementations, the mobile device 800 supports carrieraggregation, thereby providing flexibility to increase peak data rates.Carrier aggregation can be used for both Frequency Division Duplexing(FDD) and Time Division Duplexing (TDD), and may be used to aggregate aplurality of carriers or channels. Carrier aggregation includescontiguous aggregation, in which contiguous carriers within the sameoperating frequency band are aggregated. Carrier aggregation can also benon-contiguous, and can include carriers separated in frequency within acommon band or in different bands.

The antennas 804 can include antennas used for a wide variety of typesof communications. For example, the antennas 804 can include antennasfor transmitting and/or receiving signals associated with a wide varietyof frequencies and communications standards.

In certain implementations, the antennas 804 support MIMO communicationsand/or switched diversity communications. For example, MIMOcommunications use multiple antennas for communicating multiple datastreams over a single radio frequency channel. MIMO communicationsbenefit from higher signal to noise ratio, improved coding, and/orreduced signal interference due to spatial multiplexing differences ofthe radio environment. Switched diversity refers to communications inwhich a particular antenna is selected for operation at a particulartime. For example, a switch can be used to select a particular antennafrom a group of antennas based on a variety of factors, such as anobserved bit error rate and/or a signal strength indicator.

The mobile device 800 can operate with beamforming in certainimplementations. For example, the front end system 803 can include phaseshifters having variable phase controlled by the transceiver 802.Additionally, the phase shifters are controlled to provide beamformation and directivity for transmission and/or reception of signalsusing the antennas 804. For example, in the context of signaltransmission, the phases of the transmit signals provided to theantennas 804 are controlled such that radiated signals from the antennas804 combine using constructive and destructive interference to generatean aggregate transmit signal exhibiting beam-like qualities with moresignal strength propagating in a given direction. In the context ofsignal reception, the phases are controlled such that more signal energyis received when the signal is arriving to the antennas 804 from aparticular direction. In certain implementations, the antennas 804include one or more arrays of antenna elements to enhance beamforming.

The baseband system 801 is coupled to the user interface 807 tofacilitate processing of various user input and output (I/O), such asvoice and data. The baseband system 801 provides the transceiver 802with digital representations of transmit signals, which the transceiver802 processes to generate RF signals for transmission. The basebandsystem 801 also processes digital representations of received signalsprovided by the transceiver 802. As shown in FIG. 9 , the basebandsystem 801 is coupled to the memory 806 of facilitate operation of themobile device 800.

The memory 806 can be used for a wide variety of purposes, such asstoring data and/or instructions to facilitate the operation of themobile device 800 and/or to provide storage of user information.

The power management system 805 provides a number of power managementfunctions of the mobile device 800. In certain implementations, thepower management system 805 includes a power amplifier supply controlcircuit that controls the supply voltages of the power amplifiers 811.For example, the power management system 805 can be configured to changethe supply voltage(s) provided to one or more of the power amplifiers811 to improve efficiency, such as power added efficiency (PAE).

As shown in FIG. 9 , the power management system 805 receives a batteryvoltage from the battery 808. The battery 808 can be any suitablebattery for use in the mobile device 800, including, for example, alithium-ion battery.

FIG. 10A is a schematic diagram of one embodiment of a packaged module900. FIG. 10B is a schematic diagram of a cross-section of the packagedmodule 900 of FIG. 10A taken along the lines 10B-10B.

The packaged module 900 includes radio frequency components 901, asemiconductor die 902, surface mount devices 903, wirebonds 908, apackage substrate 920, and an encapsulation structure 940. The packagesubstrate 920 includes pads 906 formed from conductors disposed therein.Additionally, the semiconductor die 902 includes pins or pads 904, andthe wirebonds 908 have been used to connect the pads 904 of the die 902to the pads 906 of the package substrate 920.

The semiconductor die 902 includes a true power detection system 945,which can be implemented in accordance with any of the embodimentsherein. Thus, the true power detection systems herein can be integratedon-chip, for instance, as a silicon integrated solution. In certainimplementations, the semiconductor die 902 includes circuitry inaddition to the true power detection system 945. For example, a poweramplifier can be included on the semiconductor die 902 on-chip with thetrue power detection system 945. In another implementation, the poweramplifier is included on another semiconductor die that is attached tothe packaging substrate 920. Thus, in certain implementations thepackaged module 900 includes two or more semiconductor dies.

The packaging substrate 920 can be configured to receive a plurality ofcomponents such as radio frequency components 901, the semiconductor die902 and the surface mount devices 903, which can include, for example,surface mount capacitors and/or inductors. In one implementation, theradio frequency components 901 include integrated passive devices(IPDs). In certain implementations, one or more antennas are included inand/or on the package substrate 900.

As shown in FIG. 10B, the packaged module 900 is shown to include aplurality of contact pads 932 disposed on the side of the packagedmodule 900 opposite the side used to mount the semiconductor die 902.Configuring the packaged module 900 in this manner can aid in connectingthe packaged module 900 to a circuit board, such as a phone board of amobile device. The example contact pads 932 can be configured to provideradio frequency signals, bias signals, and/or power (for example, apower supply voltage and ground) to the semiconductor die 902 and/orother components. As shown in FIG. 10B, the electrical connectionsbetween the contact pads 932 and the semiconductor die 902 can befacilitated by connections 933 through the package substrate 920. Theconnections 933 can represent electrical paths formed through thepackage substrate 920, such as connections associated with vias andconductors of a multilayer laminated package substrate.

In some embodiments, the packaged module 900 can also include one ormore packaging structures to, for example, provide protection and/orfacilitate handling. Such a packaging structure can include overmold orencapsulation structure 940 formed over the packaging substrate 920 andthe components and die(s) disposed thereon.

It will be understood that although the packaged module 900 is describedin the context of electrical connections based on wirebonds, one or morefeatures of the present disclosure can also be implemented in otherpackaging configurations, including, for example, flip chipconfigurations.

Applications

Some of the embodiments described above have provided examples ofdynamic antenna array management in connection with wirelesscommunications devices. However, the principles and advantages of theembodiments can be used for any other systems or apparatus that benefitfrom any of the circuits and systems described herein.

For example, antenna arrays can be included in various electronicdevices, including, but not limited to consumer electronic products,parts of the consumer electronic products, electronic test equipment,etc. Example electronic devices include, but are not limited to, a basestation, a wireless network access point, a mobile phone (for instance,a smartphone), a tablet, a television, a computer monitor, a computer, ahand-held computer, a personal digital assistant (PDA), a microwave, arefrigerator, an automobile, a stereo system, a disc player, a digitalcamera, a portable memory chip, a washer, a dryer, a copier, a facsimilemachine, a scanner, a multi-functional peripheral device, a wrist watch,a clock, etc. Further, the electronic devices can include unfinishedproducts.

CONCLUSION

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Likewise, the word “connected”, as generally used herein, refers to twoor more elements that may be either directly connected, or connected byway of one or more intermediate elements. Additionally, the words“herein,” “above,” “below,” and words of similar import, when used inthis application, shall refer to this application as a whole and not toany particular portions of this application. Where the context permits,words in the above Detailed Description using the singular or pluralnumber may also include the plural or singular number respectively. Theword “or” in reference to a list of two or more items, that word coversall of the following interpretations of the word: any of the items inthe list, all of the items in the list, and any combination of the itemsin the list.

Moreover, conditional language used herein, such as, among others,“may,” “could,” “might,” “can,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. A power amplifier system comprising: a power amplifier configured to receive a radio frequency signal at an input and to output an amplified radio frequency signal at an output; an antenna configured to transmit the amplified radio frequency signal; a directional coupler having a through line and a coupled line, the through line electrically connected between the output of the power amplifier and the antenna; a first switch and a second switch; and a combiner configured to generated a combined signal based on combining a first coupled signal received from a first end of the coupled line through the first switch and a second coupled signal received from a second end of the coupled line through the second switch.
 2. The power amplifier system of claim 1 further comprising a power detector configured to generate a power detection signal based on detecting a power of the combined signal.
 3. The power amplifier system of claim 2 further comprising an analog-to-digital converter configured to digitize the power detection signal.
 4. The power amplifier system of claim 1 further comprising a termination impedance, the second switch configured to provide the second coupled signal to the combiner in a first mode and to connect the second end of the coupled line to the termination impedance in a second mode.
 5. The power amplifier system of claim 4 wherein the first switch is further configured to provide the first coupled signal to the combiner in the first mode and to output a forward power signal in the second mode.
 6. The power amplifier system of claim 1 wherein the through line is U-shaped and the coupled line is U-shaped.
 7. The power amplifier system of claim 1 wherein the amplified radio frequency signal is a millimeter wave signal.
 8. A method of power detection in a radio frequency communication system, the method comprising: amplifying a radio frequency signal to generate an amplified radio frequency signal using a power amplifier; providing the amplified radio frequency signal from an output of the power amplifier to an antenna by way of a through line of a directional coupler; providing a first coupled signal from a first end of a coupled line of the directional coupler to a combiner using a first switch; providing a second coupled signal from a second end of the coupled line of the directional coupler to the combiner using a second switch; and generating a combined signal based on combining the first coupled signal and the second coupled signal using the combiner.
 9. The method of claim 8 further comprising generating a power detection signal based on detecting a power of the combined signal.
 10. The method of claim 9 further comprising digitizing the power detection signal using an analog-to-digital converter.
 11. The method of claim 10 further controlling a transmit power of the radio frequency communication system based on the digitized power detection signal.
 12. The method of claim 8 wherein the through line is U-shaped and the coupled line is U-shaped.
 13. The method of claim 8 further comprising using the second switch to provide the second coupled signal to the combiner in a first mode and to connect the second end of the coupled line to a termination impedance in a second mode.
 14. The method of claim 13 further comprising using the first switch to provide the first coupled signal to the combiner in the first mode and to output a forward power signal in the second mode.
 15. A mobile device comprising: a transceiver configured to output a radio frequency signal; an antenna; and a front end system configured to process the radio frequency signal to generate an amplified radio frequency signal for transmission on the antenna, the front end system including a power amplifier configured amplify the radio frequency signal and a directional coupler having a through line and a coupled line, the through line electrically connected between an output of the power amplifier and the antenna, the front end system further including a first switch, a second switch, and a combiner configured to generated a combined signal based on combining a first coupled signal received from a first end of the coupled line through the first switch and a second coupled signal received from a second end of the coupled line through the second switch.
 16. The mobile device of claim 15 wherein the front end system further includes a power detector configured to generate a power detection signal based on detecting a power of the combined signal.
 17. The mobile device of claim 16 wherein the front end system further includes an analog-to-digital converter configured to digitize the power detection signal.
 18. The mobile device of claim 17 further comprising a baseband processor configured to process the digitized power detection signal to control a transmit power of the mobile device.
 19. The mobile device of claim 15 wherein the front end system further includes a termination impedance, the second switch configured to provide the second coupled signal to the combiner in a first mode and to connect the second end of the coupled line to the termination impedance in a second mode.
 20. The mobile device of claim 19 wherein the first switch is further configured to provide the first coupled signal to the combiner in the first mode and to output a forward power signal in the second mode. 